Office



novntn ierrttiuan srnvnns, or nrsnon', nonnnr, Tasmania, aus'rnnnie, nssrenon 'ro ntnernotrrro nine UUMPANY or aus'rnntnsrn, 'rnornrnrnnv minimum, or

MELEUURNE, VICTORIA,AUSTRALIA.

LBEQAIII.

No Drawing.

To all whom it may concern:

Be it known that I, ROYALn HrLLMAn- Srnvnns, a citizen of the United States of America, residing at Risdon, Hobart, 1n the State of 'Iasma'nla, Commonwealth of Australia, have invented certain new and useful Improvements in the Recovery of Zinc by Electrolysis, of which the following is a specification.

This invention relates to certain improve inents'in the recovery of zinc by electrolysis and refers more especially to the eleetrodeposition of zinc from zinc sulfate solutionsobtained by leaching ores, concentrates or other zinc bearing material with sulfuric acid, (or spent electrolyte) In the recovery of zinc by-electrolysis the presence of certain impurities interferes with and, detrimentally affects the deposition .of zinc and for efi'ective working it is very desirable that such impurities should be removed especially in view of the fact i that the said impurities accumulate wlth the continuous cireulationof the solutions. Some of the substances which thus adversely adect the eleetro-deposition of the zincare presentin' very small quantities (a. g1. 00-

alt) and the usual methods of urification' (with limestone and zinc dust have not been found effective for their eliminatlon.

I have discovered that if during the electrolysis of the zinc sulfate solutions there 1S present a certain small proportion of glue the deleterious efl'ect ofsuch impurities upon the electro-deposition of the zinc is materially minimized and operations can be continued with efiective results in the presence of glue under conditions which would otherwise not be possible.

I am awarethat glue has been used in v the electrodeposition oflead'for the purpose of obtaining a smooth coherent deposit ut it is generally recognized in theelectrodeposition of zinc that glue does not have this sheet and is therefore not required. fie

Specification of letters Patent. i V Patented Nov. 18., 1919..

Application filed May 6, June. serial no. author.

far as I am aware it has not been the'practlce to employ glue in the electro-deposition of 21m nor has it been known that the presence of glue would have any action inreadd a certain small proportion of glue in solutionfelther to the electrolyte before pass J ing into the cells or to the electrolyte in the.

cells. The amount of glue added is determined by the amount of impurities pres- .ent in the solution, and such an1ountfin- -creases as the impurities increase --wi'thin limits owing to the continuous circulation of the solutions. Moreover when manganese is present in the electrolyte in the form of manganese sulfate ascale of manganese' dioxid is formed on the anodes which in the presence of glue is deposited in more 00-. v herent form which 1nh1b1ts corrosion of the anodes.

I claima 1. In the recovery'of zincbyelectrolysis, the step of reducing the prejudicial eflect upon the electro-deposition of the zinc of the presence of cobalt and/0r nickel bythe addition of glue to the electrolyte prior to electrolysis; substantiallyas described.

2. In the recovery of zinc by electrolysis the step off-reducing the prejudicial effect upon the electro-deposition 0f the zinc of the presence of cobalt and/or nickel by the aditionof an animal colloid tothe electrolyte prior to electrolysis; substantially "as described. o

1 In witness whereof I have atltixed my signature in presenceof two witnesses.

, OYALE I-IILLMAN STEVENS;

if Witnesses:

EDWARD II. BUTLER, A LAN MoInT'YRE. 

